- vsnet-alert - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-alert 26476] TU Men: not much superhumps?
by Taichi Kato 03 Dec '21

03 Dec '21

TU Men: not much superhumps? Josch Hambsch has reported observations on Dec. 2. No prominent superhumps were detected but there were some variations. Let's see whether superhumps develop or not.

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[vsnet-alert 26475] PU Per: superhumps
by Taichi Kato 03 Dec '21

03 Dec '21

PU Per: superhumps Kiyota-san detected superhumps on Nov. 28.

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[vsnet-alert 26474] TCP J20441708-2037591: new SU UMa-type dwarf nova
by Taichi Kato 03 Dec '21

03 Dec '21

TCP J20441708-2037591: new SU UMa-type dwarf nova Josch Hambsch, Itoh-san and Kiyota-san have reported observations. According to the data by Hambsch, this object started to show superhumps on Nov. 30. Due to the short visibility in the evening sky, the superhump period has not been yet determined.

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[vsnet-alert 26473] TU Men possible superoutburst
by Taichi Kato 01 Dec '21

01 Dec '21

TU Men possible superoutburst As pointed out by Rod Stubbings in [vsnet-outburst 28070], TU Men has brightened after a possible precursor followed by a possible dip. This outburst may be a long-sought superoutburst. Although this object is known as an SU UMa star above the period gap, superhumps have only been recorded back to 1980! No true superoutbursts have been recorded since. https://ui.adsabs.harvard.edu/abs/1984A%26A...132..187S/abstract YYYYMMDD(UT) mag observer 20211127.510 165 (Rod Stubbings) 20211128.506 166 (Rod Stubbings) 20211129.487 125 (Rod Stubbings) 20211129.537 128 (Rod Stubbings) 20211129.646 129 (Rod Stubbings) 20211130.466 118 (Rod Stubbings) 20211130.507 118 (Rod Stubbings) As one can see in the above paper dealing with the 1980 superoutburst, the initial phase was not observed and there was a gap in the middle. These observations were made before we have sufficient knowledge about superhump evolution. Southern observers, please turn your telescope to TU Men and perform time-resolved photometry to cover the entire phases of the outburst. Such a chance may be only once in 40 years!

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[vsnet-alert 26472] Gaia21fik
by Taichi Kato 30 Nov '21

30 Nov '21

Gaia21fik http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia21fik/ Gaia21fik AT2021afrn 2021-11-15 09:19:56 197.40356 -70.83968 14.85 unknown 2021-11-29 11:52:30 bright blue hostless transient

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[vsnet-alert 26471] MASTER OT J030227.28+191754.5: WZ Sge-type dwarf nova having the largest outburst amplitude
by Keisuke Isogai 29 Nov '21

29 Nov '21

MASTER OT J030227.28+191754.5: WZ Sge-type dwarf nova having the largest outburst amplitude We reported the results of our spectroscopic and photometric observations to ATel: https://www.astronomerstelegram.org/?read=15074 Within one day, the spectra had significantly changed to that of typical dwarf nova. We also detected early superhump-like modulations. Thus this object will be the WZ Sge-type dwarf nova having the largest outburst amplitude so far.

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[vsnet-alert 26470] MASTER OT J030227.28+191754.5 light curve so far
by Denis Denisenko 29 Nov '21

29 Nov '21

I have compiled the light curve of this unusual large-amplitude optical transient using online data from ASAS-SN and ATLAS surveys available as of 09:20 UT on 2021 Nov. 29. It is posted at http://scan.sai.msu.ru/~denis/J0302+1917-LC-Nov2021.gif Note 20+16 upper limits from two different ASAS-SN units on Nov. 25.27-25.29 UT and 25.78-25.80 UT. Not a usual observing cadence by this instrument. Looks like ASAS-SN was also covering the IceCube neutrino event, and just missed the optical transient by a magnitude or so! References MASTER: ATel #15067 (Zhirkov, Kechin, Lipunov et al.) ASAS-SN: Kochanek et al., 2017 ATLAS: Tonry et al., 2018 R. Fidrich: vsnet-alert 26468 Note: MASTER-OAFA observation time was given in ATel #15067 as "5 hours later" (after MASTER-Tavrida detection, that is). I have used MJD=59545.034 for the MASTER-OAFA point with 13.4m. Time error box (+/-30 min, or 0.02 d) is smaller than the symbol size on the plot. Another note: 20.8 mag. star 2" to the west-north-west of the transient is not related to the variable itself. It has a proper motion detectable between SDSS and Pan-STARRS epochs, and at the DSS plates is was located to the south of the OT position. Most likely it is a red dwarf closer to the Sun than the MASTER OT. Finally, the progenitor has quite a blue color in SDSS: u=22.17 g=21.95 r=21.93 i=22.19 z=22.41 Denis Denisenko

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[vsnet-alert 26469] MASTER OT J030227.28+191754.5: KWS pre- and post-discovery data
by Hiroyuki Maehara 29 Nov '21

29 Nov '21

According to the KWS data, the object was at V~12 mag on Nov. 27.558 and V~11.8 mag on Nov 28.558-28.559. object date(UT) mag. code err. MASTER_OT_J030227.28+191754.5 20211123.56269 <122V KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56272 <112Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56303 <127V KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56307 <108Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56358 <122V KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56361 <111Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56392 <123V KW2 -- MASTER_OT_J030227.28+191754.5 20211123.56396 <110Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57029 <126V KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57032 <111Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57066 <124V KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57068 <107Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57122 <112Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211125.57156 <108Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56848 <130V KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56852 <117Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56883 <131V KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56887 <113Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56940 <129V KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56943 <113Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56976 <126V KW2 -- MASTER_OT_J030227.28+191754.5 20211126.56979 <117Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211127.55807 11.916V KW2 0.158 MASTER_OT_J030227.28+191754.5 20211127.55810 <114Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211127.55841 12.084V KW2 0.182 MASTER_OT_J030227.28+191754.5 20211127.55845 <114Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211127.55899 <110Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211127.55934 <113Ic KW2 -- MASTER_OT_J030227.28+191754.5 20211128.55787 11.757V KW2 0.131 MASTER_OT_J030227.28+191754.5 20211128.55791 11.577Ic KW2 0.370 MASTER_OT_J030227.28+191754.5 20211128.55822 11.702V KW2 0.125 MASTER_OT_J030227.28+191754.5 20211128.55825 11.224Ic KW2 0.268 MASTER_OT_J030227.28+191754.5 20211128.55876 11.852V KW2 0.143 MASTER_OT_J030227.28+191754.5 20211128.55880 11.220Ic KW2 0.269 MASTER_OT_J030227.28+191754.5 20211128.55911 12.211V KW2 0.197

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[vsnet-alert 26467] Spectroscopic and Photometric follow-up of MASTER OT J030227.28+191754.5
by Keisuke Isogai 29 Nov '21

29 Nov '21

Spectroscopic and Photometric follow-up of MASTER OT J030227.28+191754.5 We performed spectroscopic and photometric observations. We propose that this object is a possible narrow-lined He nova or very large-amplitude WZ Sge-type dwarf nova. https://www.astronomerstelegram.org/?read=15072 This object is showing enigmatic behavior. Further observations are strongly encouraged!

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[vsnet-alert 26466] ZTF J210411.01-010202.3 = Gaia21fhx
by Taichi Kato 28 Nov '21

28 Nov '21

ZTF J210411.01-010202.3 = Gaia21fhx http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia21fhx/ Gaia21fhx AT2021afpm 2021-11-26 11:04:51 316.04638 -1.03367 15.17 unknown 2021-11-27 16:08:10 transient on blue PanSTARRS source, candidate CV 2MASS 210411.030 -010201.98 (2000.0) 16.605 15.908 15.659 210411.0 -010202 (2000.0) ZTFJ210411.01-010202.3 r=19.566 (18.456-19.939) P=0.0296 210410.999 -010202.33 (2000.0) Gaia_DR2_6917174984897161088 plx=1.906(0.408) dismod=8.6 pmra=0.711(0.799) pmdec=-15.658(0.716) G=19.443 BP=20.723 RP=18.266 210410.999 -010202.34 (2000.0) Gaia_EDR3_6917174984897161088 plx=2.116(0.328) dismod=8.4 pmra=0.956(0.329) pmdec=-14.974(0.268) G=19.416 BP=20.761 RP=18.273 Bright in 2MASS (but red). Dwarf nova with a long orbital period?

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